The present invention relates an outboard motor provided with an improved fuel tank structure and an improved fuel tank support structure.
In a large or middle sized outboard motor which is equipped to a large-sized boat or like, a fuel tank is generally arranged on the side of a hull of the boat. However, in a small sized outboard motor which is mounted to a small sized boat or like, a fuel tank is often arranged inside an engine cover covering an engine.
Inside the engine cover, the fuel tank is generally arranged such that a mounting seat is provided for the engine or engine cover and the fuel tank is then mounted to the mounting seat through rubber or elastic member by means of bolts or like.
In such arrangement in which the fuel tank is fixed by means of bolts or like, however, when the engine is vibrated by any reason, a boss portion of the fuel tank may be damaged or dismounted from the fixed portion, thus being defective.
Furthermore, the fuel tank fixing method by using such mounting seat and bolt means requires additional parts or elements, which may result in manufacturing cost increasing or deteriorated workability, thus being disadvantageous.
In the meantime, in the case where the fuel tank is arranged inside the engine cover, it is also troublesome and inconvenient to remove the engine cover every time of feeding (pouring) oil, and in order to eliminate such defect, only a fuel pouring port is often disposed outside the engine cover.
In order to arrange the fuel pouring port to a position outside the engine cover, it is necessary to form an opening or hole to the engine cover, which requires to seal such opening so as to prevent sea water or like from entering inside the engine cover through the opening.
In general, however, in a conventional structure, the fuel tank disposed inside the engine cover is formed through a blow-molding process, so that degree of freedom for selection of outer configuration of the fuel tank is severely limited. Accordingly, it is difficult to dispose a bracket or like, for holding a grommet, integrally with the fuel tank and it is hence necessary to additionally arrange another bracket for holding the grommet, which results in an increased number of parts or elements and an increased number of assembling steps, thus increasing manufacturing cost and making assembling steps complicated.
The present invention was conceived in consideration of the above defects or drawbacks encountered in the prior art mentioned above and an object of the present invention is to provide an outboard motor particularly provided with an improved fuel tank structure capable of fixing the fuel tank without using specific fixing member or element such as bolt and also capable of holding a grommet with an easy construction.
The above and other objects can be achieved according to the present invention by providing an outboard motor which comprises:
an engine having a crankcase in which a crankshaft is perpendicularly arranged;
an engine starting device disposed above the engine in an installed state of an outboard motor;
an engine cover covering the engine and comprising a lower engine cover section fixed and covering a lower portion of the engine and an upper engine cover covering an upper portion of the engine to be detachable;
a drive shaft housing which is disposed below the engine and in which a drive shaft operatively connected to the crankshaft extends perpendicularly;
a gear case disposed below the drive shaft housing; and
a fuel tank disposed inside the engine cover so as to extend vertically along an axial direction of the crankshaft,
wherein the fuel tank is disposed in a space in the engine cover in front of the engine on a hull side and the fuel tank is clamped and supported from the vertical direction by the lower cover section of the engine cover and the engine starting device.
In a preferred embodiment, the fuel tank is supported by a plurality of tank support bosses provided for peripheral equipments disposed to a periphery of the fuel tank, and a plurality of engagement grooves are formed to surface portions of the fuel tank so as to respectively correspond to and engaged with the engine tank support bosses.
The peripheral equipments include a starter cover of the engine starting device having a front end lower surface to which one of the tank support boss is mounted, and an engine support plate constituting the engine lower cover section and having a front end upper surface to which another one of the tank support bosses is mounted. The plural tank support bosses further include a pair of lateral tank support bosses mounted to a front surface of the crankcase. Thus, the fuel tank is supported at vertical two portions and two portions on the side surface of the fuel tank.
The fuel tank has an outer configuration having a shape along an inside shape of the engine cover.
The engine cover may be formed of synthetic resin.
The fuel tank comprises a tank body mounted to the engine, a fuel pouring member (passage) extending upward from the tank body externally of the engine upper cover section through an insertion hole formed thereto, and a fuel pouring port formed to an extending end of the fuel pouring member.
The insertion hole formed to the engine upper cover section is closed by a grommet from an inside of the engine and a grommet holding flanged member is disposed to the fuel tank. The grommet holding flanged member is fixed to the fuel tank by press-fitting means or fusing means. The grommet holding flanged member has a plate shape and is disposed above the engine starting device and to an intermediate portion of the fuel pouring member directly below the fuel pouring port.
The grommet holding flanged member has size and shape, in a plan view, substantially overlapping with size and shape of the engine starting device.
The functions and advantageous effects attainable by the present invention will be made clear from the following descriptions with reference to the accompanying drawings as well as further characteristic features of the present invention.